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Showing result 1 - 5 of 16 swedish dissertations matching the above criteria.

  2. 1. Electromagnetic transformer modelling including the ferromagnetic core

    Author : David Ribbenfjärd; Göran Engdahl; David Jiles; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power transformer; hysteresis; dynamic hysteresis; dynamic magnetization; eddy currents; excess losses; leakage flux; winding model; core model; magnetic measurements; magnetic materials; Electric power engineering; Elkraftteknik;

    Abstract : In order to design a power transformer it is important to understand its internal electromagnetic behaviour. That can be obtained by measurements on physical transformers, analytical expressions and computer simulations. READ MORE

  4. 2. Electromagnetic Modelling of Power Transformers with DC Magnetization

    Author : Seyed Ali Mousavi; Göran Engdahl; S. V. Kulkarni; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer; Hysteresis; DC magnetization; GICs; FEM; reluctance network method;

    Abstract : DC currents that flow through the ground can be injected to the star windings of power transformers from their grounded neutral points and close their path with transmission lines. The geomagnetically induced currents (GICs) and AC/DC convertors of high voltage direct current (HVDC) systems are the sources of such DC currents. READ MORE

  5. 3. Diagnosis of Moisture in Transformer Insulation - Application of frequency domain spectroscopy

    Author : Chandima Ekanayake; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; moisture content; diagnostic methods; modelling; polarisation depolarisation currents PDC ; frequency domain spectroscopy FDS ; dielectric response measurements; Oil-impregnated pressboard paper insulation; Karl Fischer titration KFT ; conductivity; ageing;

    Abstract : This thesis presents application of dielectric response measurements for identifying condition of high voltage insulation in power transformers. Results of such measurements, incorporated with different modelling techniques, allow to estimate moisture content in solid part of transformer insulation. READ MORE

  6. 4. Design, Modelling and Verification of Distributed Electric Drivetrain

    Author : Nimananda Sharma; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric vehicles; system modelling; mechanical-hardware-in-the-loop; real-time modelling; power-hardware-in-the-loop; Distributed drivetrain;

    Abstract : The electric drivetrain in a battery electric vehicle (BEVs) consists of an electric machine, an inverter, and a transmission. The drivetrain topology of available BEVs, e.g., Nissan Leaf, is centralized with a single electric drivetrain used to propel the vehicle. READ MORE

  7. 5. Electromagnetic Modelling of Power Transformers for Study and Mitigation of Effects of GICs

    Author : Seyedali Mousavi; Göran Engdahl; Ebrahim Rahimpour; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transformer; hysteresis; DC magnetization; GMD; GICs; FEM; reluctance network method; low frequency transients; core losses; winding losses; eddy current losses; transformator; hysteresis; DC; likströmsmagnetisering; GMD; GIC; FEM; reluktansnätverksmodell; lågfrekventa transienter; kärnförluster; lindningsförluster; virvelströmsförluster; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Geomagnetic disturbances that result from solar activities can affect technological systems such as power networks. They may cause DC currents in power networks and saturation of the core in power transformers that leads to destruction in the transformer performance. READ MORE